Device for feeding out fibres at production of thermosettable fibre reinforced products

ABSTRACT

A device for feeding out reinforcement fibres at production of thermosetting plastic products, which device includes at least one magazine spool for a fibre thread (15), and guiding means (17, 18, 19) for guiding the fibre thread to a fibre feedout head (13). The feedout head is provided with feed means (21, 22, 31, 32) for feeding the fibre thread from the magazine spool coil via the guiding means, and cutting means (26, 26a, 27), which enables cutting off the fibre thread. The feed means of the feedout head (13) means includes on one hand driven feed rollers (21, 22), which form at least one nip for the fibre thread (15) and on the other hand fibre ejecting means (31, 32). The cutting means (26, 26a, 27) are individually driven and placed between the feed rollers (21, 22) and the fibre ejecting means (31, 32).

TECHNICAL FIELD

The present invention refers to a device for feeding out reinforcementfibres at production of thermosetting plastic products, which deviceincludes at least one magazine spool for a fibre thread, and guidingmeans for guiding the fibre thread out to a fibre feedout head, whichfeedout head is provided with feeding means for feeding the fibre threadfrom the magazine spool via the guiding means, and cutting means, whichenables cutting of the fibre thread, wherein the feeding means of thefeedout head includes on one hand driven feed rollers, which form atleast one nip for the fibre thread and on the other hand fibre ejectingmeans.

BACKGROUND OF THE INVENTION

The production of fibre reinforced thermosetting plastic products isdifficult to automate, since the quality of the product is highlydependent on the orientation of the fibres, with regard to how theproduct will be subjected to load. Modern quality conditions usuallyimplies that a product should have an exact amount of fibres, which areoriented for maximum strength, without the fibres projecting out throughthe outer plastic layer of the product.

One manufacturing method implies that fibre carpets are preformed todesired shape and exerts the preform to heat treatment for activation ofa bonding agent keeping the fibres together. The edge of the preform,produced in this manner is usually cut manually, so that excess fibresare removed at the edges before the final casting of thermosettingplastic takes place. The application of fibre carpets and the need ofmanual removal of excess fibres means that this manufacturing method isexpensive. Furthermore, the strength of the fibres is utilized only to asmall degree.

Consequently, there are possibilities for improvements in this field,which improvements by automation of the manufacturing process providesbetter use of the material, so that structures repeatedly can be madelighter, material acquisitive and technically more advanced. Thereby,even possibilities of reducing the problems of poor working environmentand wear of manpower are obtained.

THE TECHNICAL PROBLEM

The object of the present invention is to provide a device for feedingout reinforcement fibres at production of thermosettable products, whichmakes it possible to automate the supply of reinforcement fibres to aproduct, e.g. by use of an industrial robot, thus that preforms may beproduced repeatedly from fibre thread with the fibres arranged inendless coils, cut fibres with regular orientation and cut fibres withirregular orientation.

THE SOLUTION

For this purpose the invention is characterized in that the cuttingmeans are driven individually from the feed rollers and located betweensaid rollers and the fibre ejecting means, and that the cutting meansincludes a driven knife roller with outwardly projecting knife bladesand a backing roller, which is operable to positions in engagement withor non-engagement with the knife roller.

DESCRIPTION OF THE DRAWINGS

Hereinafter the invention will be described with reference toembodiments shown in the accompanying drawings, on which

FIG. 1 shows schematically a feeding out device according to theinvention as seen from the side,

FIG. 2 shows in bigger scale an angled section forming part of thefeeding out device,

FIG. 3 shows in a scale corresponding to FIG. 2, as seen from the side,a feedout head forming part of the feeding out device.

DESCRIPTION OF EMBODIMENTS

The device schematically shown in FIG. 1 includes a magazine 10 forfibre thread spools 11, a magazine 12 for pulverulent bonding agent, afeedout head 13 for fibre thread and bonding agent, and a control center14.

The feedout head 13 is preferably mounted on a robot arm 41, which isfreely movable in the room and is governed by a micro processor 42,which can be programmed.

The fibre thread 15 runs via a feeding device up to the feedout head 13.The feeding device includes end pieces 16, straight tubular pieces 17and angled pieces 18. The end piece 16 situated closest to the threadspool 11 is provided with connection for compressed air, which pressuremedium is used to advance the end on the fibre thread through thefeeding device to the feedout head 13, which during this time issituated in a docking position adjacent the feedout end piece 16 of thefeeding device. When the end of the thread has reached the feedout head13, the fibre thread will be pulled through the feeding device by meansof feed rollers. The feedout head 13 thereupon can move from its dockingposition.

One of the angled sections 18 is shown more in detail in FIG. 2 and itincludes a rectangular block 18 with holes 18a located at right angleagainst each other and intended for the tubes 17 leading in to a centralchamber 18b. The chamber 18b on one hand is equipped with a deflectionwall 18c, which is adapted to deflect the fibre end fed by compressedair, from one tube to the other, and on the other hand an angled needle18d, which forms a contact surface for the thread, when this is pulledthrough the feeding device. The angled needle 18d is positioned thus inrelation to the tubes 17, that the thread will not engage the inner sideof the tubes in the area of the angled pieces 18.

The feedout head 13 is shown more in detail in FIG. 3 and it isaccommodated in a housing 19. A guide tube 20 for the fibre thread 11 isprovided in the housing 19. The guide tube 20 extends in to the nipbetween two rollers 21, 22, roller 21 of which is displaceable supportedand urged in a direction towards the other roller 22 by means of apressure spring 23. The roller 22 is driven in a speed adjustable mannerat a speed V₁ by means of a non shown driving motor. The speedadjustment is achieved by means of pulse counting means 24, which areconnected to the control center 14.

The rollers 21, 22 advance the fibre thread 15 through a tube 25, angledat about 90°, which opens in the nip between a knife roller 26 and abacking roller 27. The knife roller 26 is equipped with three knifeblades 26a, evenly spaced apart along the periphery of the roller. Theroller 26 can be driven in a speed-adjustable manner at a speed V₂ bymeans of a non shown driving motor. The speed adjustment is achieved bymeans of pulse counting means 28, which are connected to the controlcenter 14. The backing roller 27 is displaceable mounted in a verticalguide 29 and operable by means of a pneumatic piston cylinder 30.

The feedout head 13 is provided with a feeding out tube 31, which isequipped with a connection 32 for compressed air, which pressure mediumis used for feeding out cut thread pieces 15a. Furthermore the feedouttube 31 is provided with a connection 33 (see FIG. 1) to a control unitfor supply of pulverulent bonding agent from the magazine 12. The tube31 is electrically insulated from the other part of the feedout head 13.By suitable choice of material the fibre thread can be staticallycharged electrically at its passage through the tube by electricalcharge supply means 43 at the tube 31. This arrangement implies, thatthe pulverulent bonding agent will adhere to the fibre fed out.

A deflection plate 34 (see FIG. 1), which is pivotable from oneoperating position to another, is operable by means of a pneumaticpiston cylinder 35. When the deflection plate 34 is in inactiveposition, the cut fibres 15a will be fed out on a surface orientedirregularly in the longitudinal direction. When the deflection plate 34is in operative position, the cut fibres 15a will be fed out on asurface oriented in a regular longitudinal direction.

With the device described above the fibre thread can be fed out as acontinuous fibre coated with bonding agent. The robot arm thereby cancontrol the feedout head 13 in such a manner, that the endless fibre isoriented in an advantageous manner, e.g. in coils around a hole thatshall receive a bolt. Alternatively the fibres may be cut in exactlydesired lengths, by starting the knife roller 26 and rotating it incontact with the backing roller 27 at a speed which gives an appropriateknife frequency in proportion to the speed of the fibre, which iscontrolled by the speed of the driving roller 22.

At each instant of cutting, the fibre thread 15 is pulled forwardintermittently a short distance at a speed higher than the normaladvance speed of the thread. For ascertaining that there are no jerks inthe thread, which can cause thread ruptures or increased wear on thedriving rollers 21, 22, the tube 25 bent to arc-form serves as a jerkequalizer. Normally the driving rollers 21, 22 press the thread 15through the tube 25, thus that the thread follows the outer radius ofthe tube interior. When a knife blade then grips the thread to cut itoff against the backing roller 27, there is a certain play for the fibrethread in the advance area between the feeding rollers 21, 22 and thefibre ejecting means, which play is illustrated in FIG. 2 by the doublearrow 36, which shows the play between the fibre thread 15 and innerradius of the interior of tube 25.

The magazine 12 is provided with feeding means 37 for exact dosage ofthe bonding agent powder. These means 37 are connected to the controlcenter 14. The magazine 10 for fibre thread 15 is furthermore designedas an electronic scale, which also is connected to the control center14. This means that the fibre and powder supply can be exactlycontrolled, thus that a preform for casting a thermosettable plasticproduct can be built up with a correct amount of fibres and bondingagent.

The invention furthermore can be utilized for production of glass fibrereinforced thermoplastic materials in one single step withoutpre-forming.

The above described device can be doubled within the same cover 19 forfeeding out two fibre threads. At the same time it is easy to equip therobot arm with two such feedout heads, whereby the robot can handle fourthreads in parallel.

The invention is not limited to the embodiments described here above,but several variants are conceivable within the scope of the followingclaims. The feedout head 13, for instance, may be connected to conduitsfor feeding out liquid bonding agents, or some type of plastic, e.g.polyurethane. The feedout tube 31 can be replaced by a sliding plate,channel or a gutter.

I claim:
 1. A device for feeding reinforcement fibres for production ofthermosettable plastic products, said device comprising:at least onemagazine for containing a fibre thread; and a fibre feedout head,guiding means for guiding the fibre thread from the magazine to thefibre feedout head, the feedout head being provided with feeding meansfor feeding the fibre thread from the magazine through the guidingmeans, and cutting means positioned and arranged after the feeding meansin the path of the fibre thread and adapted to cut the fibre thread,wherein the feeding means of the feedout head includes driven feedrollers which form at least one nip for the fibre thread, and fibreejecting means, wherein the cutting means are driven from the feedrollers and are located between the feed rollers and the fibre ejectingmeans, the cutting means including a driven knife roller with outwardlyprojecting knife blades and a backing roller which is opposite the kniferoller and is operable to either a position of engagement with the kniferoller to permit cut fibres to be ejected from the fibre ejecting meansor to a position of non-engagement with the knife roller to permitcontinuous fibres to be ejected from the fibre ejecting means.
 2. Adevice according to claim 1, wherein the fibre thread runs in an arcuatepath between the feed rollers and the fibre ejecting means.
 3. A deviceaccording to claim 2, further comprising: a tube preceding the feedrollers in the path of the fiber thread, wherein the fibre threadtravels through the tube, at least a portion of the tube is bent in anarcuate shape, the tube having a diameter which allows a predeterminedamount of play for the fibre thread in an advance area between the feedrollers and the fibre ejecting means, the play enabling the end of thefibre thread to be moved forward intermittently a short distance at aspeed higher than a speed of the fibre thread through the feed rollers.4. A device according to claim 1, wherein the guiding means for guidingthe fibre thread from the magazine to the feedout head includes aplurality of straight tubes and angled sections interconnecting thetubes, the angled sections having an inner side having supporting meansfor the fibre thread providing a small contact surface for the thread.5. A device according to claim 1, wherein the fibre ejecting means aredriven pneumatically and include means for giving the fibre thread acharge of static electricity.
 6. A device according to claim 5, whereinthe fibre ejecting means are provided with a connection for a controlledsupply of pulverulent bonding agent.
 7. A device according to claim 6,further comprising a control means including means for adjustment of thesupply of pulverulent bonding agent.
 8. A device according to claim 1,wherein the feedout head is moveable to selectively orient fibresejected from the fibre ejecting means.
 9. A device according to claim 8,wherein the feedout head is mounted on a robot arm, the robot arm beingadapted to effect the movement of the feedout head.
 10. A device forfeeding reinforcement fibres for production of thermosettable plasticproducts, said device comprising:at least one magazine for containing afibre thread; fibre feedout head, guiding means for guiding the fibrethread from a magazine to the fibre feedout head, the feedout head beingprovided with feeding means for feeding the fibre thread from themagazine through the guiding means, and cutting means positioned andarranged after the feeding means in the path of the fibre thread andadapted to cut the fibre thread, wherein the feeding means of thefeedout head includes driven feed rollers which form at least one nipfor the fibre thread, and fibre ejecting means, wherein the cuttingmeans are driven individually from the feed rollers and are locatedbetween the feed rollers and the fibre ejecting means, the cutting meansincluding a driven knife roller with outwardly projecting knife bladesand a backing roller which is operable either to a position ofengagement with or to a position of non-engagement with the kniferoller; measuring means for continuous weighing of an amount of fibrethread fed from the magazine; and control means associated with themeasuring means for controlling the feed rollers to feed a selectedamount of fibre thread from the magazine.
 11. A device according toclaim 10, wherein the control means includes means for control of thebacking roller and for adjustment of the driving of the knife roller.12. A device according to claim 10, further comprising a fibredeflection plate pivotally mounted downstream of the fibre ejectingmeans such that the fibre deflection plate is pivotable between anoperative and an inactive position.
 13. A device for feeding outreinforcement fibres for production of thermosettable plastic products,said device comprising:a magazine for containing a fibre thread; afeeder for feeding the fibre thread from the magazine, the feederincluding a plurality of driven feed rollers which form a nip for thefibre thread; a guide for guiding the fibre thread from the magazine tothe feeder; a cutter adapted to cut the fibre thread, the cutterincluding a driven knife roller with outwardly projecting knife bladesand a backing roller which is opposite the knife roller; and a fibreejector, the cutter being located between the feeder and the fibreejector, the backing roller being operable either to a position ofengagement with the knife roller to permit cut fibres to be ejected fromthe fibre ejector or to a position of non-engagement with the kniferoller to permit continuous fibres to be ejected from the fibre ejector.14. A device according to claim 13, further comprising a scalecontinuously weighing an amount of fibre thread fed from the magazine,and a controller associated with the scale and controlling the feeder tofeed a selected amount of fibre thread from the magazine.
 15. A deviceaccording to claim 14, wherein the controller further controls thebacking roller and adjusts the driving of the knife roller.
 16. A deviceaccording to claim 14, further comprising a fibre deflection platepivotally mounted downstream of the fibre ejector such that the fibredeflection plate is pivotable between an operative and an inactiveposition.
 17. A device according to claim 13, wherein the fibre threadruns in an arcuate path between the feed rollers and the fibre ejector.18. A device according to claim 17, further comprising: a tube precedingthe feed rollers in the path of the fiber thread, wherein the fibrethread travels through a tube, at least a portion of the tube is bent inan arcuate shape, the tube having a diameter which allows apredetermined amount of play for the fibre thread in an advance areabetween the feed rollers and the fibre ejector, the play enabling theend of the fibre thread to be moved forward intermittently a shortdistance at a speed higher than a speed of the fibre thread through thefeed rollers.
 19. A device according to claim 13, wherein the guideincludes a plurality of straight tubes and angled sectionsinterconnecting the tubes, the angled sections having an inner sidehaving a support for the fibre thread providing a small contact surfacefor the thread.
 20. A device according to claim 13, wherein the fibreejector is driven pneumatically and is adapted to give the fibre threada charge of static electricity.
 21. A device according to claim 20,wherein the fibre ejector is provided with a connection for a controlledsupply of pulverulent bonding agent.
 22. A device according to claim 21,further comprising a controller controlling the supply of pulverulentbonding agent.
 23. A device according to claim 13, further comprising afibre feedout head, wherein the feeder, the cutter and the fibre ejectorare provided in the fibre feedout head.
 24. A device according to claim23, wherein the fibre feedout head is moveable to selectively orientfibres ejected from the fibre ejector.
 25. A device according to claim24, wherein the feedout head is mounted on a robot arm, the robot armbeing adapted to effect the movement of the fibre feedout head.